Picture projecting and sound reproducing machine



y 1932- M. CORCORAN 1,858,435

PICTURE PROJECTING AND SOUND REPRODUCING MACHINE Filed April 6, 1931 2 Sheets-Sheet l at: 1:113; 141:; {.Z'iZiiJI 5:;

Lam renceMC brmran y 17, 1932- L. M. CORCORAN 1,858,485

PICTURE PROJECTING AND SOUND REPRODUGING MACHINE Filed April 6.- 1951 2 Sheets-Sheet 2 Lau renceM.30rc0r2n Patented May 17, 1932 UNITED STATES PATENT OFFICE LANR'ENcE M. oo ncoRAN, or CALDWELL, NEW JERSEY, ASSIGNOR 'ro onvnr. n. PLAT- TER AND HOWARD FRANKEL, or NORTH VERNON, INDIANA PICTURE IEROJ'ECTING AND SOUND REPRQDUCING MACHINE Application filed April 6,

This invention relates to apparatus for reproducing sound froma film on which it has been previously recorded by photographyandto reproduce it in synchronism with pictures on the same film.

An object of the invention is to provide means for eliminating undesirable effects due to vibration of a number of parts of a machine.

Another object is to provide means for compensating for relative difierences in speed necessary between certain movable parts of the machine.

A still further general object is to simplify and improve sound reproducing machines of this type.

Referring to the accompanying drawings, which are madea part hereof and on which similar reference characters indicate similar parts,

Figure 1 is a side view in elevation of p cture projecting and sound reproducing units of the machine,

Figure'2, a view ure 1,

Figure '3, a detail view of the exciter lamp and associated elements,

Figure 4, a view of Figure 3 taken from the right,

Figure 5, a plan view of Figure 3,

Figure 6, a'detail view of mechanism for winding up the film after it has passed through the machine, the view showing particularly the driving connection to the winding up mechanism, and

Figure 7, a section on line 7-7 of Figure 6.

In the drawings numeral 10 indicates a casing in which picture projecting and sound reproducing mechanism are housed. At 11 and 12 are shown reels from which the film 13 is unwound and wound up respectively. -The picture projecting machine in the housing 10 consists among other things of the lamp 14, lens 15, reflector 16, light gate 17, all of well known construction. The film is moved through the machine over sprockets 18, '19, 20 and 21, all of which sprockets are driven at the same speed. An intermittently driven sprocket 22 moves the film intermittently through the picture projecting mechafrom the right of Fig nism in well-known manner. In the lower half of the casing 10 is mounted the sound reproducing unit. This consists of an exciter lamp 23 mounted upon a bracket 24. In order to permit necessary adjustment of the exciter lamp adjustable nuts 25 and 26 permit securing the exciter lamp in any desired vertical position. Bracket 24 is provided with a reenforced rib 53 and the bracket 24 may be secured to the back of the casing 10 by means of screws inserted in holes 54. Any necessary lateral adjustment of the exciter lamp 23 to aline it properly may be secured by providing a hole through the reenforced rib 53 on the bracket somewhat larger than the stem 55 of the eXciter lamp so that the lamp may be moved to the desired position and secured there by the nuts 25, 26 which lock it in place. At 28 is shown as a whole the optical unit through which the light beams pass from the exciter lamp to a light sensitive cell 29, passing through the sound track on the film 13. The optical unit 28 is suitably mounted and secured in a bearing 27. A clamping screw 56 holds the optical unit in position after it has been adjusted properly.

To those familiar with the art of sound film reproduction, it is well known that objectionable vibration noises are converted into electrical energy and amplified along with light wave fluctuations. This result is produced by the filament in the exciter lamp being set in vibration by the mechanical moving parts of the projector and vibrating out of phase. With reference to the optical unit this vibration is imparted to the light beam which passes through the optical unit and strikes the photo-electrical cell. By the construction just described the exciter lamp and the optical unit are both rigidly mounted upon a single bracket 24 so that they vibrate in phase instead of one with respect to the other. This vibration of course does not cause any relative movement of the parts and hence does not aifect the light. It may be clearly seen therefore that objectionable vibration is eliminated.

Pick-up and amplifying mechanism are associated with the light sensitive cell 29 but since this forms no part of the invention in this case it will not be described in detail.

The film is moved through the machine by a motor 45 through a suitable belt or chain 46 which passes around pulleys or sprockets 47 and 48. The sprocket 47 is mounted on the shaft which carries sprocket 20. Sprocket 48 is mounted on a shaft which carries a pinion 59. This pinion drives pinion 60 through idle pinion 61. Pinion 58 is on the shaft which carries sprocket 18. There is a 1 to 4 ratio between sprocket 20 and sprocket 47. There must be the same ratio between pinion 60 and pinion 59 so that sprockets 18 and 20 may be driven at the same speeds. The motor makes 1440 R. P. M. The sprockets l8 and 20 therefore make 360 R. P. M. This moves the picture through the machine at 90 feet per minute which is the usual speed desired. In order to insure correct tension on the chain or belt there is provided an idle sprocket 49 mounted upon the end of an arm 50. A pin 51 passing through the arm 50 and having a spring 52 at its lower end provides means for applying proper tension to the idler sprocket so as tomaintain the driving chain or belt 46 under correct tension to eliminate any sag or flapping.

Means are shown in Figures 6 and 7'for driving the film takeup reel and to permit the necessary slippage due to the increasing diameter of the reel as the film is wound thereon. A shaft 31 having a bevel gear 30 on its inner end is driven by any suitable gear connection within the housing 10. The shaft 31 has a cup-like enlarged end 33 within which the end of a shaft 32 en ages, the shaft 32 having a pin 57 engageable in'a slot in the cup 33 to provide driving connection. The housing 34 is provided with a plate 33 in which housing the shaft 32 is mounted. The whole housing is secured to the side of the casing 10 by means of bolts 36 which pass through the casing 10 and are threaded into the plate 35. This holds the whole assembly against the plate 10 so as to maintain the shafts 31 and 32 in driving connection. The outer end of the shaft 32 is provided with a worm 37 which meshes with a worm gear 38 looselymounted on a shaft 39. Disks 40 and 41 keyed to the shaft 39 are frictionally held against the sides of the worm wheel 38 by means of a tension spring 42. A nut 43 having a flange 44 engaging the spring 42 provides means for tensioning the spring to regulate the friction with which disks 40 and 41 engage the worm wheel 38. In order to provide the best wearing qualities and also to reduce noise the worm 37 is preferably a steel gear and the worm wheel 38 is preferably a fiber gear of some suitable construction. A fiber gear built up of layers of fabric and bakelite subjected to great heat and pressure results in a most efficient gear for this purpose it is noiseless, has great'wearing qualities and yet provides suflicient friction when engaged by the disks 40 and 41 to give a driving contact for the shaft 39. The shaft 39 engages the spool 12 upon which the film is wound. The worm 37 and the worm gear 38 and associated parts are housed within a casing 58 as shown in Figure 7. This casing is designed to hold oil in which the parts might run to provide necessary lubrication.

in operation the reel containing the film which is being wound up is driven at a relatively high rate of speed during the beginning of the winding. As the winding continues the reel enlarges and it is necessary that it be driven at a slower rate of speed. This is provided byslippage between the fiber wheel 38 and the disks 40 and 41 engagingit. cient friction to drive it but yet are not pressed against it so tight as to injure the film or to cause too great tension on the film as the whole is pulled from the sound reproducing mechanism.

It will be obvious to those skilled in the art that various changes may be made in our device without departing from the spirit of the invention and therefore we do not limit ourselves to what is shown in the drawings and described in the specification, but only as incheated by the appended claims.

Having thus fully described our said invention, what we claim as new and desire to secure by Letters Patents, is:

-1. In a picture projecting and sound reproducing machine, a casing for housing the various elements, a plate rigidly secured to said casing, a shelf projecting from the lower edge of said plate and adapted to receive an exciter lamp, a socket for said lamp comprising a sleeve threaded on its exterior and adapted to enter an opening in said shelf and adjusting nuts carried by said sleeve one above and one below said shelf to adjust said sleeve and lamp vertically, a lug projecting from the upper edge of said plate and adapted to receive an optical unit and a brace connecting said shelf and lug to'form a rigid structure, substantially as set forth.

2. In a picture projecting and sound reproducing machine, a casing for housing the various elements, the combination of an exciter lamp and optical unit, a bracket for mounting the same comprising a vertical plate adapted to be secured to said casing, a horizontal shelf formed integral with and projecting from the lower edge of said late and adapted to support said lamps, a orizontal lug formed integral with and projecting from the upper edge of said plate and adapted to support said optical unit and a brace formed integral with said shelf, plate and lug to form a rigid structure, substantially as set forth.

3. In a picture projecting and sound reproducing machine, a casing-for housing the The disks engage the fiberwith suflililll.

various elements, a plate rigidly secured to said casing, a shelf projecting from the lower edge of said plate and adapted to receive an exciter lamp, a lug projecting from the upper edge of said plate and adapted to receive an optical unit and a brace connecting said shelf and lug to form a rigid structure, substantially as set forth.

In witness whereof, I have hereunto set my hand at North Vernon, Indiana this th day of March, A. D. nineteen hundred and thirty-one.

LAURENCE M. CORCORAN. 

